1. Field of the Invention
The present invention relates to a mold, and more particularly to a plastic injection mold for molding a plastic article.
2. The Related Art
Nowadays, plastic articles are mostly manufactured by injection molding method. In general, a plastic injection mold comprises an upper insert, a lower insert and a runner system. A mold cavity is defined between the upper insert and the lower insert when they are combined together. The runner system is provided for injecting molten plastic material from a nozzle of an injection molding machine to the mold cavity. The runner system generally includes a sprue, a runner and a gate. The sprue connects the nozzle and the runner. The gate is an entrance of the mold cavity. The molten plastic material is injected into the runner from the sprue, and then flows into the mold cavity through the gate to form plastic articles. As known by the skilled in the field, the gate directly influences appearance, deformation, molding constringency rate and strength of molded articles. The gate style is chosen in accordance with the molded article. However, the conventional gate design is apt to make the molded article disfigure, causing possible material shortage, weld marks, shrinkage, gate-white-flecks, warpage, brittleness, degradation, etc. when the molded article is very small and thin.